On-demand in-line-blending and supply of chemicals

ABSTRACT

This in-line active and reverse calculating mass balance blending system can maintain a chemical at desired control points, such as with respect to concentration, temperature, and/or pressure, while the output flow rate is changing dynamically to a point of use. A blending unit is configured to receive and blend at least two species and deliver a mixture at selected concentrations to points of use. A controller can be configured to determine a mass balance to maintain the concentrations in the mixture using information from metrology systems and a flow in an output to the at least one point of use. The controller also can be configured to maintain a concentrations in the mixture within a concentration range by controlling flow rates to the blending unit.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to the provisional patent applicationfiled Nov. 27, 2019 and assigned U.S. App. No. 62/941,152, thedisclosure of which is hereby incorporated by reference.

FIELD OF THE DISCLOSURE

This disclosure relates to combining fluids to form a chemical mixture.

BACKGROUND OF THE DISCLOSURE

Many industrial processes and commercial products combine two or morefluids (liquids or gases) together to form a defined mixture. Batchblending is the process of chemical blending where the chemicalconstituents are added independently and mixed in a tank before beingmade available for use. Continuous (in-line) blending is the process ofchemical blending where the chemical constituents are combined in-linewithin a conduit while flowing to points of use and are immediatelyavailable for use at the points of use. Semi-batch blending is theprocess of chemical blending where the chemical constituents arecombined in-line and then held in a tank/vessel for dispense at a latertime. Semi-batch blending allows for blended batch compositionqualification prior to the release for consumption or use. Semi-batchingis the most common embodiment used in the blending technology sectors ofindustry.

Typically, combining fluids is performed in discrete batches. In such abatch process, a quantity of the first fluid is added, followed by aquantity of the second fluid. These two fluids are mechanically mixed,and the resulting mixture is sampled. If necessary, additionalquantities of either the first or the second fluid can be further addedto refine the composition of the mixture. Once the desired compositionis achieved, the batch is released for use, transferred to anintermediate vessel, or transferred directly to the end user. This typeof batching or blending process is common to many industrial segmentsincluding semiconductor processing, pharmaceutical products, biomedicalproducts, food-processing products, household products, personal careproducts, petroleum products, chemical products, and other generalindustrial liquid products.

Batch processing, or batching, has many drawbacks and limitations. Forexample, usually large tanks are required. Since this process can betime-consuming, large-volume batches are typically prepared at the sametime. This large scale requires substantial manufacturing space, createsvariations between batches, and large batch volumes dictate a relativelyfixed and inflexible manufacturing schedule. Large volumes are typicallybatched in order to overcome the relative imprecision of constituentfluid measurement. Large volumes help to reduce these errors as apercentage of the total batch quantity.

Another drawback of batching is that the batch frequently changes itsrheological or chemical properties over time. This aging effect iscommon to many formulations and over time, and it forces manyadjustments to be made prior to sending the composition to theintermediate or end user. Batching can also lead to open or partiallyopen tanks with fluids exposed to the atmosphere. This can lead tounwanted chemical contamination, chemical degradation, or microbialcontamination.

Batching can also lead to difficulties in mixing the fluid componentstogether in large volumes. Mixing can require prolonged agitation tomake a homogeneous mixture. It is common for different levels of a largetank to have different proportionate mixtures of the fluids. Largevolumes typically committed to batching also cause cleaning to be slow,laborious, and difficult to automate. Large volumes of cleaningeffluents are produced, leading to issues of waste and contamination.

Because of these numerous shortcomings and limitations, alternativemeans of fluid products manufacturing have been sought. One alternativemethod to batch processing is known as continuous or in-line blending.Continuous or in-line blending embodies the notion of combiningconstituent fluids to form a fluid product only as needed or on anon-demand basis. Essentially, the product is made on-demand and at afixed rate required. The rate required is typically based on the demandof the fluid using processes, filling machine packaging, or overall useof the liquid product being made.

A continuous or in-line blending system can eliminate the large batchpreparation and holding tanks, which leads to a small system volume,more product compounding flexibility, faster product formulationturnaround, and a substantially lower capital cost. Continuous andin-line blending can reduce waste, cleanup time, and effluent volumes.Furthermore, the mixing is simplified and results in more homogeneousformulations. The product aging effects are also largely eliminated.However, it can be challenging to build and operate a continuous orin-line blending system with the maximum degree of accuracy, flexibilityof use, and versatility of application in a broad range of commercialsectors.

Numerous designs for continuous or in-line stream blending have beenproposed, originating from various liquid processing industries, such aselectronic, semiconductor, beverage processing, and food processing.These designs attempted to develop and market continuous in-line flowproportioning or blending systems based upon ratios using flow controldevices, flow meters, and proportional-integral-derivative (PID)feedback control loops. This is a type of feedback controller whoseoutput, a control variable, is generally based on the error between someuser-defined set point and some measured process variable. Each elementof the PID controller refers to a particular action taken on the error.

Proportional refers to error multiplied by a gain, K. This is anadjustable amplifier. In many systems, K is responsible for processstability. Too low and the process value (PV) can drift away. Too highand the PV can oscillate. Integral refers to the integral of errormultiplied by a gain, K. In many systems, K is responsible for drivingerror to zero, but setting K too high invites oscillation, instability,or integrator windup or actuator saturation. Derivative refers to therate of change of error multiplied by, K. In many systems, K isresponsible for system response. Too high and the PV will oscillate. Toolow and the PV will respond sluggishly. Derivative action can amplifyany noise in the error signal.

In general, these designs rely on regulating a continuous flow of theliquid streams using variable orifice valves or speed controlled pumps.A flow rate signal from a flow meter, most often a Coriolis mass flowmeter or metrology, is used to proportionately modulate the flow controldevice in order to attempt to maintain a desired ratio of flows amongthe streams. Another signal represents overall system demand rate andcan be used to proportionately modulate the summed flow of the entiresystem.

Several major design problems are encountered with continuous or in-lineblending systems using this architecture. First, as the overall outputof the system is increased or decreased, the rate of change capabilityor response time constant of each stream will vary one from the next.Thus, with a varying output command signal, each stream reacts at adifferent rate causing loss of ratio flow. This is further aggravated bythe overshoot or undershoot of each stream as a new set point isreached. As each stream flow rate changes, it can perturb the flow rateof the other stream or streams causing hunting or oscillations. Thesecommon control problems can cause serious loss of blended streamaccuracy. PID loop controllers are designed to control complex systemsthat are not inherently designed for stability or ease of control. PIDloop controllers deal with the interacting, multiple dependent andindependent variables of a flow stream, in a non-real time, statisticalway and fight changing parameters on an historical basis.

Another problem can arise when a feedback signal change causes the flowto briefly go below or above the permissible range of the flow metergenerating the feedback signal. This can occur even with software orhardware safeties. Maintaining flow through a Coriolis mass flow meteror other flow monitoring devices within a defined range may be needed toachieve satisfactory accuracy.

Another problem encountered with these designs and the PID controlarchitecture arises with the need to start and stop the processes or themajor flow streams of the system. When a stop-start event occurs, it isdifficult to bring the system back on-line with balanced and accurateflow, metrology stability, and overall in-specification blending. Thisproblem has been so persistent that nearly all installed systems haveresorted to the use of a surge tanks, or intermediate vessels of up toseveral hundred gallons capacity, to allow blending flow to continueduring processing and machine stoppages.

Even with the use of a surge tank and intermediate vessels, if blendingflow must stop, upon re-start the flow streams must either be divertedto drain until correct flow rates or metrology response arereestablished because of a prolonged pause or stoppage. Otherwise, thesurge tank or vessels must be large to allow wrong unmatched flow ratiosto be statistically “diluted” to prevent loss of accurate blending.Either method results in substantial waste, decreased blending accuracy,increased system complexity, and increased system volume, thus depletingthe sought after advantages of continuous or in-line blending.

Additionally the applications described above are based on fixedincoming flow rates, pressures, temperatures, and concentration ofspecific materials to achieve specific blend concentrations at a knownflowrate. Thus, these systems are designed for a fixed flowrate oroverall rate in production.

Therefore, there is a need in the industries for an in-line blendingsystem and operation techniques that address weaknesses ofabove-mentioned technologies.

BRIEF SUMMARY OF THE DISCLOSURE

Embodiments disclosed herein can accommodate on-demand dynamic change inflow rates by the end users or points of use while maintaining a preciseblend accuracy. Embodiments of the blending system can produce mixturesand supply them to multiple end users or points of use at variableon-demand or changing production rates while maintaining ahigh-resolution blend accuracy at independent control points. Theblending system can correct a blended product that may have beentemporarily stored in a tank, vessel, or supply line prior to deliveryto or on route to the end user or to single or multiple points of use.The blending system can have an ability to track and confirm thechemical compositions of the initial system's entering chemicalcomponents, the associated intermediate blends, and the various finalmixture blends while the systems output production rate varies from, forexample, 0.0 liter per minute (lpm) flow volume, while stepping up tovarious changing flow rates as different users turn on and off the blendsolution usages. Such system by example can move, for example, from 0.0lpm to 1.0 lpm to 2.0 lpm and various other increasing volumes until amaximum design value is reached. Maximum rate may be based upon the flowcontrol devices physical limits. The blending system can provide blendedproducts without the need for fixed volumes in storage vessels or pointof use blended product supply flows with little to no waste generated atstartup or rinse process cycles. The blending system can define eachincoming material's composition with in-line metrology and feed thisinformation forward for blend control. This feed forward information canbe used to achieve an in-line blend accurately with use of proportionalflow control (PFC) and metrology that is feeding back information forblend control, which validates a mixture when demanded with real-timeactive calculation of mass balance for control of the overall systemmixtures being produced. This can verify the mixture in-line at alltimes with metrology and control the process on-demand.

A blending system for maintaining a mixture at a desired concentrationis provided in a first embodiment. The blending system comprises a firstspecies input that provides a first species; a second species input thatprovides a second species; a blending unit in fluid communication withthe first species input, the second species input, and an output that isin fluid communication with at least one point of use; a first metrologysystem configured to measure a concentration of the first species in thefirst species input; a second metrology system configured to measure aconcentration of the second species in the second species input; and acontroller in electronic communication with the blending unit, the firstmetrology system and second metrology system. The blending unit isconfigured to blend the first species and the second species therebyforming a mixture. The controller is configured to determine a massbalance to maintain the concentration in the mixture within 1% of aconcentration range using information from the first metrology system,the second metrology system, and a flow in the output to the at leastone point of use. The controller is also configured to maintain aconcentration in the mixture within 1% of the concentration range bycontrolling a flow rate for at least one of the first species or thesecond species to the blending unit based on the mass balance.

The blending system can further include a first species source in fluidcommunication with the first species input and a second species sourcein fluid communication with the second species input. The first speciessource provides the first species. The second species source providesthe second species.

The blending system can further include an output metrology system inthe blending unit. The output metrology system can configured to measurethe concentration in the mixture upstream of the point of use. Theoutput metrology system can be in electronic communication with thecontroller. The controller can use information from the output metrologysystem to determine the mass balance.

The blending system can include a plurality of the points of use eachhaving one of a plurality of the outputs.

The controller can be further configured to receive information relatedto a demand rate at the point of use and increase a flow rate of themixture from the blending unit to the point of use while maintaining theconcentration within 1% of the concentration range.

The controller can be further configured to receive information relatedto a demand rate at the point of use and decrease a flow rate of themixture from the blending unit to the point of use while maintaining theconcentration within 1% of the concentration range.

The blending unit can be configured to achieve a homogenous solution ofthe mixture at less than 99% of a maximum designed flow rate for thesystem.

The blending unit can include an input flow path; an output flow path; achemical injection nozzle proximate the input flow path; a directionalflow perforated plate downstream of the input flow path and the chemicalinjection nozzle; a homogenizing turbulence mix zone void disposeddownstream of the input flow path and the chemical injection nozzle andupstream of the directional flow perforated plate; a flow directionalcone disposed downstream of the input flow path and the chemicalinjection nozzle and upstream of the homogenizing turbulence mix zonevoid; a first mixing zone flow directional cone disposed downstream ofthe homogenizing turbulence mix zone void and upstream the directionalflow perforated plate; and a turbulence break void disposed between thedirectional flow perforated plate and the output flow path. The chemicalinjection nozzle can include an insertable injection nozzle.

The blending system can further include a directional valve in fluidcommunication with the blending unit. The controller can be inelectronic communication with the directional valve. The controller canbe configured to control the directional valve to circulate or drain themixture in the blending unit. The blending system can further include aheater, a pressure control, and a pump in fluid communication with theblending unit between the blending unit and the output.

The blending system can be configured to provide the mixture to theoutput at a plurality of flow rates sequentially over a period of time.The concentration in the mixture can be within 1% of the concentrationrange for the plurality of flow rates.

The controller can be configured to control the blending unit and a flowrate of the mixture to the output such that a first species in themixture from the first species input is maintained within a range ofapproximately 0.01% to approximately 0.1% of the concentration range andsuch that a second species in the mixture from the second species inputis maintained within a range of approximately 0.01% to approximately0.1% of the concentration range.

The blending system can further include a third species input in fluidcommunication with the blending unit and a third metrology system inelectronic communication with the controller. The third species inputprovides a third species for the mixture. The third metrology system canbe configured to measure a concentration of the third species in thethird species input. The concentration of the third species can be usedin the mass balance.

The blending system can further include an ultra-pure water input influid communication with the blending unit.

The point of use may be a semiconductor processing tool.

A method of providing blended mixture to a point of use is provided in asecond embodiment. The method comprising providing a flow of a firstspecies to a blending unit; providing a flow of a second species to theblending unit; blending the first species and the second species in theblending unit to produce a mixture; distributing the mixture to a pointof use via an output in fluid communication with the blending unit;measuring a concentration of the first species in the flow of the firstspecies with a first metrology system; measuring a concentration of thesecond species in the flow of the second species with a second metrologysystem; and maintaining, using a controller in electronic communicationwith the first metrology system and second metrology system, aconcentration in the mixture within 1% of a concentration range based ona mass balance. The maintaining includes determining the mass balance tomaintain the concentration in the mixture within 1% of the concentrationrange using information from the first metrology system, the secondmetrology system, and a flow in the output to the at least one point ofuse.

The blending unit can deliver the mixture on-demand to the point of use.

The maintaining can include, using the controller, changing a flow rateof the flow of the first species or a flow rate of the second species.

The maintaining can include, using the controller, increasing a flow ofthe mixture when the concentration in the mixture is outside theconcentration range.

Increasing the flow can include opening a drain valve in fluidcommunication with the blending unit.

The method can further include measuring the concentration in themixture upstream of the point of use with an output metrology system.Information from the output metrology system can be used to determinethe mass balance.

Determining the mass balance to maintain the concentration in themixture can use information about concentration of the mixture from thepoint of use.

The method can further include increasing at least one of the flow ofthe first species or the second species when the concentration in themixture is outside the concentration range.

The method can further include decreasing at least one of the flow ofthe first species or the second species when the concentration in themixture is outside the concentration range.

The system can be configured to provide the mixture to the point of useat a plurality of flow rates sequentially over a period of time. Theconcentration in the mixture can be within 1% of the concentration rangefor the plurality of flow rates.

Each of the plurality of flow rates can be from 1 liter per minute to 20liters per minute.

Distributing the mixture can be to a plurality of the points of use.

Maintaining can include compensating for decomposition of the firstspecies or the second species in the blending unit.

The method can further include providing a flow of a third species tothe blending unit and measuring a concentration of the third species inthe flow of the third species with a third metrology system that is inelectronic communication with the controller. Determining the massbalance can use the concentration of the third species from the thirdmetrology system. The third species may decompose at least one of thefirst species or the second species in the mixture.

The method can further include providing a flow of ultra-pure water tothe blending unit.

The first species and the second species may be each an aqueous acid,base, solvent, salt, or slurry.

DESCRIPTION OF THE DRAWINGS

For a fuller understanding of the nature and objects of the disclosure,reference should be made to the following detailed description taken inconjunction with the accompanying drawings, in which:

FIG. 1 is a block diagram illustrating an embodiment of an on-demand,in-line blending system with a circulation loop to blend to temperatureaccording to the present disclosure;

FIG. 2 is a block diagram illustrating another embodiment of anon-demand, in-line blending system according to the present disclosure;

FIG. 3 is a block diagram illustrating an embodiment of athree-component, on-demand blending system with circulating volumeaccording to the present disclosure;

FIG. 4 is a block diagram illustrating an embodiment of a two-component,on-demand blending system with circulating volume according to thepresent disclosure;

FIG. 5 is a block diagram illustrating an alternative embodiment of atwo-component on-demand blending system according to the presentdisclosure;

FIG. 6 is a block diagram illustrating another alternative embodiment ofa two-component on-demand blending system according to the presentdisclosure;

FIG. 7 is a block diagram illustrating further alternative embodiment ofa two-component on-demand blending system according to the presentdisclosure;

FIG. 8 is a block diagram illustrating yet another alternativeembodiment of a two-component on-demand blending system according to thepresent disclosure;

FIGS. 9A-9C illustrate an embodiment of a blending/mixing pointaccording to the present disclosure;

FIGS. 10A-10E illustrate an embodiment of an injection nozzle that canbe used in the blending/mixing point of FIG. 9;

FIG. 11 is a diagram of a method according to the present disclosure;and

FIGS. 12-17 an example of maintaining the concentration ranges in themixture using a mass balance.

DETAILED DESCRIPTION OF THE DISCLOSURE

Although claimed subject matter will be described in terms of certainembodiments, other embodiments, including embodiments that do notprovide all of the benefits and features set forth herein, are alsowithin the scope of this disclosure. Various structural, logical,process step, and electronic changes may be made without departing fromthe scope of the disclosure. Accordingly, the scope of the disclosure isdefined only by reference to the appended claims.

Systems and methods for on-demand in-line-blending and supply ofchemicals are disclosed. Methods of the present disclosure include anin-line active and reverse calculating mass balance blending system,which maintains a chemical at desired control points, such as withrespect to concentration, temperature, and/or pressure, while the outputflow rate changes dynamically to the point of use. Embodiments disclosedherein include a blending unit configured to receive and blend at leasttwo chemicals and deliver a mixture, at selected concentrations topoints of use. The blending system can further include a controllerconfigured to maintain at least one mixture within a selectedconcentration range within the chemical formed. The controller controlsat least one operation of the blending unit to maintain theconcentration of the mixture within a selected concentration range, suchas at one or more points of use. The operation can be continuous and canmaintain the concentration of the mixture at all times during operation.A change in flow rate of the inputs and outputs of the blending systemcan be detected. When flow changes, the blending system can activelycalculate the mass balance required to maintain concentration of themixture at a new flowrate while maintaining within the chemical targetrange.

The mass balance can be specified at the design phase when the massbalance, also called a material balance, is the application ofconservation of mass to design the physical systems. Therefore, massbalances are used in engineering to design chemical systems. Byaccounting for material entering and leaving a system in total mass,their flows are identified to select what components are used to achieveblended product at a specified or given production rate. Theseproduction rates are typically fixed in volume when producing theblended solutions to the feed, filler, or using process points. Processpoints can be known as points of use.

As shown generally in FIGS. 1 and 2, systems according to the presentdisclosure define each incoming material's composition with in-linemetrology and feed the measured composition parameters forward forcontrol. In-line blend accuracy can use PFC and metrology feedbackdownstream for control. Validation of the mixture can be accomplishedwith real-time active calculation of mass balance for enhanced control.The in-line mixture composition can be ensured with metrology andcontrol of the process in the on-demand system. FIG. 1 illustrates ablending system 100 including a circulation loop to facilitate blendingto specific temperature points. FIG. 2 shows an alternative embodimentof a blending system 200 without a circulation loop. The optionalprocess control 113 for the blending unit 105 may include an outputmetrology system for the mixture in the blending unit 105.

Embodiments of the blending system 100 can maintain a mixture at adesired concentration. The blending system 100 can include a firstspecies input 109 that provides a first species and a second speciesinput 110 that provides a second species. The first species input 109and second species input 110 can be a pipe or tube. The first speciesand second species may be different. The blending system 100 also canoptionally include an ultrapure water (UPW) input 111, hot UPW input112, and/or other inputs.

A first species source 101 can be in fluid communication with the firstspecies input 109 to provide the first species. A second species source102 can be in fluid communication with the second species input 110 toprovide the second species. The first species source 101 and secondspecies source 102 may be, for example, a tank, reservoir, or container.

The first species source 101 and second species source 102 can deliverthe first and second species to the blending unit 105. One or more pumpsmay be used to transfer the first species and/or second species to theblending unit 105. The controller 106 is configured to control deliveryof the first species and the second species at selected concentrationsand at varying flow rates to the blending unit 105 such that theblending unit 105 provides the mixture to the point of use at a desiredflow rate while maintaining first species within a concentration rangeand/or the second species within a second concentration range of themixture delivered to the point of use. Valves can be used to controldelivery of the first species and the second species.

The blending unit 105 can include a flow change detection units and aninline pump. The PFCs can be used to provide in-line blend accuracyusing feedback from the metrology in the blending system 100. Theblending unit 105 can provide an in-specification blend, which caninclude real-time validation. The blending unit also can provideoptional heating, such as using a resistance heater, boiler, or otherheating system.

In an embodiment, the blending system 100 can include a third speciesinput (not illustrated) in fluid communication with the blending unit105. The third species input provides a third species for the mixture.The third species input may be in fluid communication with a thirdspecies source. The third species may be different from the firstspecies and/or the second species. While a third species input and thirdspecies are disclosed, more than three species inputs or species can beused. The first species, second species, and third species are typicallynot pure water, though each may contain water in a solution or mixture.

In an instance, the third species can decompose at least one of theother species in the mixture that is being provided to the points ofuse. For example, a peroxide can decompose during transport or storage.

The first species, second species, or other species can be fluids. Thesefluids can be solutions, aqueous chemicals, liquids, or gases. Inanother instance, the chemical input can be a powder, which can betransported as a powder or with a liquid or gel.

A blending unit 105 can be in fluid communication with at least one ofthe first species input 109 or the second species input 110. Theblending unit 105 also can be in fluid communication with an output 107that is in fluid communication with one or more point of use. Forexample, there may two or more points of use. Each of the points of usecan have one of the outputs 107 or points of use can share an output107. In an instance, the point of use is a semiconductor processingtool. The blending system 100 may be in substantially close proximity tothe semiconductor process tool. Other points of use are possible andthis is only one example.

The blending unit 105 is configured to blend at least one of the firstspecies or the second species thereby forming a mixture. The blendingunit 105 can be configured to receive and blend at least two species anddeliver a mixture at selected concentrations to at least one point ofuse that requires a demanded volume of the mixture. The blending unit105 also can adjust the temperature or pressure of the mixture, such aswith heaters or pumps. Differences in temperature or pressure of themixture from a desired range or value also can be determined andcompensated for.

A first metrology system 103 can be configured to measure aconcentration of the first species in the first species input 109. Asecond metrology system 104 can be configured to measure a concentrationof the second species in the second species input 110. The metrologysystems can include inductively coupled conductivity or refractive indexsensors to detect the concentration in the inputs.

A controller 106 can be in electronic communication with the blendingunit 105, the first metrology system 103, and the second metrologysystem 104. The blending unit 105 on demand delivers the mixture to thepoint of use during system operation. The controller 106 can define theincoming material composition using defined information to continuallyand/or actively determine the mass balance required, achieve the desiredmixture, validate the mixture by maintaining the required mass balance,and ensure with in-line active metrology and feedback. The controller106 can be configured to determine a mass balance to maintain theconcentration or concentrations in the mixture within 1% of aconcentration range or ranges using information from the first metrologysystem 103, the second metrology system 104, and a flow in the output107 or outputs 107 to the at least one point of use. The controller 106also can be configured to maintain a concentration or concentrations inthe mixture within 1% of the concentration range or ranges bycontrolling a flow rate for at least one of the first species or thesecond species to the blending unit 105. Thus, a flow rate of solutioninto and/or out of the blending system 100 changes when theconcentration range changes.

The controller 106 can determine the mass balance by subtracting anyoutputs to the points of use and any consumption within the system froma sum of the inputs to the system and any generation within the system.There may be accumulation within the system (i.e., mass buildup) if someof the mixture is contained in the blending unit 105. While accumulationmay occur, accumulation also may be minimized or may be zero. Thedetermination may be made every 10-100 ms using metrology readings withthe various flowrates. A material balance can account for material forthe blending system 100 derived at a specific concentration while at adesired flow rate and including a total volume used. The blending system100 configuration and quantities of interest (e.g., mass of a component,total mass, moles of an atomic species, etc.) can be defined. The massbalance can use information about the flow rates of the inputs andconcentrations of the inputs and the outputs.

In an instance, a volume of the blending unit 105, a volume of theoutput 107, and a concentration of the desired mixture are known. Theoutgoing flowrate to the point of use is determined. The concentrationof first species and second species in the mixture can be determined andthe flowrates in the first species input 109 and/or second species input110 can be adjusted. This can use a PID equation. The blending unit 105can determine that mixture is being used at one or more of the points ofuse. Flow rates can be determined by, for example, a flow meter or aposition of valves in the blending system 100. For example, a steppermotor position of a valve can be used to determine flow rate if thevalve size and dimensions are known. Thus, if the valve opening positionusing the stepper motor is known, then the flow rate through the valveis known.

In the embodiments disclosed herein, there can be multiple PIDs runningin concert. These PIDs can include feedback control from single PVs orfeed-forward plus feedback that incorporate multiple PVs. The PIDs canbe used to set a bias starting position on the flow control valves.Cascading and/or cascading with feedback can be used.

Changes can be detected and managed by adjusting the flow controldevices to maintain the desired flow, pressures, and/or concentration.

An example mixture includes a solvent with UPW (76.16% wt), inhibitor(0.66% wt), oxidizer (0.33% wt), acid (4.31% wt), base (2.83% wt), andsuspended solid (15.71% wt). FIGS. 12-17 illustrate different flowrates, POU volume, and valve conditions to maintain the concentrationranges in the mixture using a mass balance.

Temperature of the first species and/or second species can be monitoredwhen determining concentration in the first species input 109 and/orsecond species input 110. Temperature can affect conductivity of thefirst species and/or second species, so differences in temperature canbe compensated for.

The flow rate can be controlled by adjusting one or more of the valvesin the blending system 100, such as in a PFC or outputs 107. Optionalbooster pumps also can be used in the first species input 109 and/orsecond species input 110.

In an embodiment, the blending system 100 can follow usage at the pointsof use. Thus, the blending system 100 may match operation at the pointsof use. Flow of the mixture to the points of use may match usage at thepoints of use. This can be particularly helpful with mixtures thatdecompose or have a short shelf-life.

Embodiments of the blending system 100 can be based on preloadedconditions. For example, at start-up there can be preloaded conditionssuch as incoming supply component pressures and assay values. Thus, theproportional control valve positions can be determined and when theair-operated valve opens in a blend sequence can be determined.Additionally, loaded forward and back pressure regulating devices can beused during operation. The instruments in the blending system 100 can beset up with zero averaging employed at the start of a sequence thatallows readings to follow in real-time and applying averaging as theoperation enters into steady state running. Thus, the components of theblending system 100 work in concert to react when the sequences start.The minimum time in response is approximately 100 ms and typical flux inflows and pressures is from 0.1 to 0.5 on the PV value.

In an instance, the controller 106 is configured to control the blendingunit 105 and the flow rates of mixture to the point of use such thatmixture is maintained within a range of approximately 0.01% toapproximately 0.1% of a concentration target of the mixture being usedat the point of use. In another instance, the controller 106 isconfigured to control the blending unit 105 and the flow rates ofmixture to the point of use such that mixture is maintained within theconcentration target of the mixture being used at the point of use.

In an instance, the controller 106 can be configured to control theblending unit 105 and a flow rate of the mixture to the output 107 suchthat a first species in the mixture from the first species input 109 ismaintained within a range of approximately 0.01% to approximately 0.1%of the concentration range of the mixture and such that a second speciesin the mixture from the second species input 110 is maintained within arange of approximately 0.01% to approximately 0.1% of the concentrationrange of the mixture.

The concentration range of the mixture or any of the input species atthe point of use can be determined by initial design requirement. Forexample, the concentration range may include a first species atapproximately 5.0% by weight of the mixture at point of use and thesecond species at approximately 1.0% by weight of the mixture at pointof use. This is only one example. Other concentration ranges arepossible.

In an instance, the controller 106 can further be configured to controla flow rate for the UPW and/or hot UPW to maintain the concentration inthe mixture.

While the first species input 109 and second species input 110 aredisclosed, plural constituent feeds can include three or more speciesinputs. Each species input can transport a different species.

The blending system 100 can include an output metrology system 108 inthe blending unit 105. The output metrology system 108 is configured tomeasure the concentration in the mixture upstream of the point of use.The output metrology system 108 can be in electronic communication withthe controller 106. The controller 106 can use information from theoutput metrology system 108 to determine the mass balance.

The metrology sensors can measure, among other things, a concentrationof the at least one species of the mixture being used by the point ofuse to provide an indication to the controller 106 when theconcentration in the mixture is within the target range or outside ofthe range.

The controller 106 can be configured to receive information related to ademand rate at the point of use. In response, the controller 106 cansend instructions to increase a flow rate of the mixture from theblending unit 105 to the point of use while maintaining theconcentration within 1% of the concentration range. The controller 106also can send instructions to decrease a flow rate of the mixture fromthe blending unit 105 to the point of use while maintaining theconcentration within 1% of the concentration range. In another instance,the blending system 100 can maintain the concentration in the mixturewithin the concentration range by delivering an increased flow rate tothe output 107 when the concentration is outside the concentrationrange.

The blending system 100 can be configured to allow an on-demand flow ofmixture to move with changing rate of use demand. Flow is controlled asrequired up and down as one or more point of use demand rates change.The blending system 100 may be capable of moving from 0.0 lpm to anyflows between and up to a designed maximum of the PFCs 106 for a givenblending system 100, such as 1 lpm, 10 lpm, 20 lpm, or 40 lpm.

One or more of the aspects and embodiments of the controller 106 asdescribed herein may be implemented using one or more machines (e.g.,one or more computing devices) programmed according to the teachings ofthe present specification, as will be apparent to those of ordinaryskill in the computer art. Appropriate software coding can readily beprepared by skilled programmers based on the teachings of the presentdisclosure, as will be apparent to those of ordinary skill in thesoftware art. Aspects and implementations discussed above employingsoftware and/or software modules may also include appropriate hardwarefor assisting in the implementation of the machine executableinstructions of the software and/or software module.

Such software may be a computer program product that employs amachine-readable storage medium. A machine-readable storage medium maybe any non-transitory medium that is capable of storing and/or encodinga sequence of instructions for execution by a machine (e.g., a computingdevice) and that causes the machine to perform any one of themethodologies and/or embodiments described herein. Examples of amachine-readable storage medium include, but are not limited to, amagnetic disk, an optical disc (e.g., CD, CD-R, DVD, DVD-R, etc.), amagneto-optical disk, a read-only memory (ROM) device, a random accessmemory (RAM) device, a magnetic card, an optical card, a solid-statememory device, an EPROM, an EEPROM, and any combinations thereof. Amachine-readable medium, as used herein, is intended to include a singlemedium as well as a collection of physically separate media, such as,for example, a collection of compact discs or one or more hard diskdrives in combination with a computer memory. As used herein, amachine-readable storage medium does not include transitory forms suchas signal transmission.

Examples of a computing device include, but are not limited to, acomputer workstation, a terminal computer, a server computer, a handhelddevice (e.g., a tablet computer, a smartphone, etc.), a web appliance, anetwork router, a network switch, a network bridge, any machine capableof executing a sequence of instructions that specify an action to betaken by that machine, and any combinations thereof. Computing deviceswill generally include one or more processors, memory, optionallynon-volatile storage, input/output devices and/or graphical userinterfaces. Computing devices may also include communication means forcommunication with remote, local, or wide area networks, includingwireless or cloud-based communications. The computing device also cancommunicate with components of the blending system 100.

The blending unit 105 can be configured to achieve a homogenous solutionof the mixture at less than 99% of a maximum designed flow rate for thesystem. For example, if the blending system 100 maximum flow is 20liters, then 99% of it would be 19.8 liters. The blend points of thefirst species and the second species may be configured to achieve ahomogenous solution with minimal volume and pressure loss when measuredfrom species inlets to a blended solutions outlet with no turbulentaffluent on the out flowing blended stream. In some embodiments thepressure loss is negligible or near zero even while achieving completemixing.

The blending system 100 can include a pressure control device such as aback pressure regulator like an active pressure-controlled pipe conduitor vessel. This pressure control device can control the pressure in theblending unit 105. Incoming chemical components enter the system atpressure and are regulated down to, for example, 45 PSIG. This becomesthe pressure entering in to the proportional flow control valve (PFCV).The control valve of the PFCV with the inlet and outlet pressure can setthe flow rate. The blending system 100 can control the delta in pressureand maintain the needed pressure in the blend channel in the blendingunit 105, which contain the two blend cells. In an example, the enteringpressure to the PFCV is controlled at 45 PSIG while the pressure on theoutlet is maintained at 15 PSIG. The blend cell's volume is greater thanthe two conduits delivering the fluid into the entrance, and the controlvalve is larger than the conduits so there is no pressure drop acrossthe blend cell. There is a measured pressure change that floats oroscillates with flow when active. The cyclical oscillations are between0.1 to 0.5 PSIG on both sides of the blend cells when measured actively

In the dynamic fixed volume embodiment of FIG. 1, the blending system100 includes a flow directional valve in fluid communication with theblending unit 105. The controller 106 is in electronic communicationwith the flow directional valve. The controller 106 is configured tocontrol the flow directional valve to circulate or drain the mixture inthe blending unit 105. The blending system 100 can further include aheater, a pressure control, and a pump in fluid communication with theblending unit 105 between the blending unit 105 and the output 107. Thepump can change the flowrate at the point of use.

For example, the controller 106 can be configured to controlmanipulation of a flow directional valve to circulate or drain tomaintain a concentration and/or pressure of supply. The drain can beconnected at the end of a point of use common conduit. For example, themixture can be drained when the solutions degrade in one or more controlelements or decomposes in a composition.

In the static fixed volume embodiment of FIG. 2, a load cell weight orflowrate reading may be configured to match the flow at the point ofuse. The contents in a static fixed volume blending system 100 may be amixture that does not generally decompose, such as an etchant.

The blending system 100 can be configured to provide the mixture to theoutput 107 at a plurality of flow rates sequentially over a period oftime. The concentration in the mixture can be within 1% of theconcentration range for the plurality of flow rates.

Flow rates may only be limited by maximum limits of the proportionalflow control devices used in the blending system 100.

In an embodiment, a semiconductor processing system or similarmanufacturing device that includes a semiconductor tool can have a pointof use. The semiconductor tool is configured to process a semiconductorcomponent, such as a semiconductor wafer. The semiconductor tool can be,for example, an etching tool, a chemical-mechanical planarization (CMP)tool, or other tools. The blending system 100 blends at least twospecies and delivers a mixture at selected concentrations to the pointof use. The point of use retains or uses a selected volume of a mixture.The controller 106 is configured to maintain at least one species withina selected concentration range in the mixture at point of use. Thecontroller 106 controls at least one operation of the blending unit 105to maintain the concentration of the at least one species within aselected concentration range within the mixture delivered to the pointof use. The controller 106 can change a flow rate of inputs into and outof the point of use when a concentration of the at least one specieswithin the mixture at point of use is outside of a target range. Changesand adjustments in flow are based on a mass balance of inputs andoutputs to maintain the concentration in the mixture.

Part of a blending unit 105 is shown in FIGS. 9A-9C. The blendingsubsystem 900 includes an input flow path 901, an output flow path 902,and a chemical injection nozzle 903 proximate the input flow path 901. Adirectional flow perforated plate 904 is downstream of the input flowpath 901 and the chemical injection nozzle 903. The directional flowperforated plate 904 diffuses the flow and helps break turbulence. Ahomogenizing turbulence mix zone void 913 is disposed downstream of theinput flow path 901 and the chemical injection nozzle 903 and upstreamof the directional flow perforated plate 904. The homogenizingturbulence mix zone void 913 creates mixing by creating turbulence. Aflow directional cone 910, which can force the flow to specific zones ofthe flow cell, is disposed downstream of the input flow path 901 and thechemical injection nozzle 903 and upstream of the homogenizingturbulence mix zone void 913. A first mixing zone flow directional cone912 is disposed downstream the homogenizing turbulence mix zone void 913and upstream the directional flow perforated plate 904. The first mixingzone flow directional cone 912 folds the two species together as the twospecies flow out of this region via a shaped hole. A turbulence breakvoid 911 is disposed between the directional flow perforated plate 904and the output flow path 902. The turbulence break void 911 can removeturbulent flow by a change in the control valve. The turbulence breakvoid 911 can have a wide accumulation point that can force laminar flow.The chemical injection nozzle 903 distributes a material in the firstmixing zone 909. The blending subsystem 900 further includes a firstmixing zone support ring 905, a final mixing zone support ring 906,chemical supply connection port 907, turbulence mixing zone void 908,and chemical injection pipe 913. The input flow path 901 and chemicalinjection nozzle 903 can transport, for example, the first species,second species, third species, UPW, hot UPW, and/or other species.

FIGS. 10A-10E illustrate an embodiment of an injection nozzle that canbe used in the blending subsystem 900 of FIG. 9. FIG. 10A is aperspective view. FIG. 10B is a top view of the embodiment of FIG. 10A.FIG. 10C is a cross-sectional view of the embodiment of FIG. 10B. FIGS.10D and 10E are additional views corresponding to FIG. 10B and FIG. 10C.

The injection nozzle of FIGS. 10A-10E can be inserted into the chemicalsupply connection port 907 of the blending subsystem 900 of FIG. 9B. Theinsertable injection nozzle (or diffusion rod) can include a tube jointwhich includes an insertion with grip joint coupling connector of whichis insertable from one horizontal side of the blending cell into oneportion of a flexible tube joint body, which is coupled to the blendingsubsystem 900 housing. The hole or holes in the injection nozzle affectchemical velocity, which affects the mixtures. The coupling connectorsurface has a flat taper that allows for multipurpose sealing of thefirst outer surface to the secondary inner surface. This then creates alocking surface for both faces to meet in joining the blending subsystem900 housing body to the coupling connector of the injection nozzle. Therod section is inserted through the coupling connector's innercircumference ensuring the sealing surface of the coupling connectorallows for the secondary outer circumference to seal with the rod beinglined up to meet the inner blending subsystem 900 folding contact point.

The injection nozzle of FIGS. 10A-10E is designed to be fullyinterchangeable and easily replaceable when inserted the injectionnozzle into the blending subsystem 900 housing. This can provide properfluid velocity for folding or mixing in the blending subsystem 900housing flow path. This can provide maximum precision control of theinjected chemistry into the blending unit 105, which can be done via theuse of tube in which contains part of the pipe joint coupling. Thedesign of the injection nozzle allows for customization of the insertionnozzle into the blending subsystem 900.

The disclosed blending unit 105 is configured to achieve a homogenoussolution with minimal volume and pressure loss when measured fromchemical inlets to blended solutions outlet, with no turbulent affluenton the out flowing blended stream. In some embodiments, volume andpressure loss is negligible or zero. One or more of the blending units105 can be used in the blending system 100 depending on the number ofpoints at which species are mixed.

In an example, an incoming species like HF is transported through theinjection nozzle into the main flow of water to achieve 100:1 dilutionof the HF. This can take 49% HF down to 0.49%.

FIGS. 3-8 illustrate various embodiments of the blending system of FIG.1 or FIG. 2.

FIG. 3 is a three-component on-demand blending system 300, which mayinclude a circulating volume circuit. In this embodiment, the blendingsystem 300 detects changes in point of use (POU) flow consumption orchanges in concentrations and/or temperature and provides blendedmaterial at the rate of consumption when being used. The system andcontrol methodology can maintain and provides blend chemical at desiredtemperature and concentration to the POU. Cold UPW parallel flow control(PFC) 150 (which can be cold or ambient temperature) and hot UPW PFC 151control final blended product temperature by providing the volume ofeach as set point required by final blend resistance temperaturedetector (RTD), other sensor, or sensors 158 and 161 via the controller170. The flow control 152 (which can include temperature or pressuremonitoring with flow monitoring) mixes and controls the flow rate of UPWcomponent of the blend solution. Feed forward control 153 can includemetrology, such as inductively couple conductivity or refractive indexsensors, to detect the incoming concentration and provide the measuredparameters to the controller 170 for mass balance calculations, whichare used to control the starting flow rate of first species. Flowcontrol 154 controls the flow rate of first species via the PID and massbalance equations provided by the controller 170. Blending/mixing pointand metrology 155 (which can include temperature or pressure monitoringwith flow monitoring) receive the flow of UPW and first species andhomogenizes, mixes, and measures the solution concentration and providesthe information to the controller 170 for use in the PID and massbalance equation. Feed-forward metrology 156 detects the incomingconcentration and provides it to the controller 170 for mass balancecalculations, which are used to control the starting flow rate of secondspecies. Flow control 157 controls the flow rate of second species viathe PID and mass balance equations provided by the controller 170.Blending/mixing point and metrology 158 (which can include temperatureor pressure monitoring with flow monitoring) receives the flow of UPWand second species and homogenizes, mixes, and measures the solutionconcentration and provides the information to the controller 170 for usein the PID and mass balance equations. In-line flow detection volume andmonitor 159 and in-line pump 160 initially receive the blended materialas it flows through the process conduit or piping to the POU tie-inpoints 166, 167, 168, 169, and through the in-line metrologies 161, withflow monitoring and change detection monitor 162, pressure control andmonitor sensors 163, flow directional valve 164, to drain 165 until theline is full of in specification mixture. At this point the valve altersstate to send the fluid to the inlet of pump 160 with the tie point toflow detector 159 until line full volume is indicated, at which pointthe blend stops.

Pump 160 circulates the solution, through the process conduit or pipingto the POU tie in points 166, 167, 168, 169, and through the in-linemetrologies 161, with flow monitoring and change detection monitor 162,pressure control and monitor sensors 163, flow directional valve 164 tothe inlet of pump 160, with the tie point to flow sensor 159. Thisprocess continues until the one or more of the POU opens and beginusing, in which case flow sensor 159 in conjunction with flow sensor 162detects the usage with the rate of use while the blender turns onsimultaneously and provides the blend at the calculated mass balance.When the POU stop taking, flow sensor 159 in conjunction with flowsensor 162 will detect the change and the blend will continue until flowsensor 159 indicates full volume, at which point the process repeats andcontinues. Additional in-line heat trace or in line heaters can be addedto maintain loop temperature. If the material in the circulation loopdegrades, directional valve 164 alters state to drain 165 until themixture is back within the specification limits as detected bymetrologies 161, at which point directional valve 164 alters state toresume the circulation through flow sensor 159 and pump 160. The processcan repeat continuously in this fashion as needed on-demand.

FIG. 4 is a two-component, on-demand blending system 400 with acirculating volume. In this embodiment, the blending system 400 detectschanges in point of use (POU) flow consumption or changes inconcentrations and/or temperature and provides blended material at therate of consumption when being used. The blending system 400 maintainsand provides blend chemical at desired temperature, and concentration tothe POU. Cold UPW 150 and hot UPW PFC 151 control the final blendedproduct temperature by providing the volume of each as set pointrequired by final blend RTD or sensor 158 and metrology 161 via thecontroller 170. Flow control 152 mixes and controls the flow rate of UPWcomponent of the mixture. Feed-forward control and metrology 153 mayinclude sensors such as inductively couple conductivity or refractiveindex sensors to detect the incoming concentration and provide it to thecontroller 170 for mass balance calculations used to control thestarting flow rate of first species. Flow control 154 controls the flowrate of first species via the PID and mass balance equations provided bycontroller 170 when lower or higher flow is require. Flow control 173can control flow of the first species and provide additional flow rangefor a higher or lower dilution ratio. Blend cell 155 and metrologyreceives the flow of UPW and first species and homogenizes, mixes, andmeasures the solution concentration and provides the information to thecontroller 170 for use in the PID and mass balance equation. In-lineflow control 154 controls the flow rate of first species via the PID andmass balance equations provided by the controller 170. In-line flowdetection volume and monitor 159 and in-line pump 160 initially receivethe blended material as it flow through the process conduit or piping tothe POU tie in points 166, 167, 168, 169, and through the in-linemetrologies 161, with flow sensor 162 monitoring for any change in flow.Flow is also through pressure control and monitor sensors 163, flowdirectional valve 164 and to drain 165 until the line is full ofin-specification mixture. At this point the valve alters state to sendthe fluid to the inlet of pump 160, with the tie point to flow sensor159, until flow sensor 159 line full volume is indicated, at which pointthe blend stops.

The flow sensor 162 in FIG. 4 or other embodiments can be a flow meter.The flow sensor 162 can provide inline flow change detection andmonitoring. The flow sensor 162 can be an individual unit or it can be avessel on scales that is monitored for a rate of change. In an example,1 kg is equal to 1 liter of a fluid with specific gravity of 1.000001.If the volume of the blending system 153 is trapped and no POU areusing, then the kg value remains constant. When a POU start using at1-liter rate, the kg changes with it. The blending system 153 volumechanges and flow sensor 162 can register a change in the trapped volumeand blender turns on and keeps pace with it.

Pump 160 circulates the solution, through the process conduit or pipingto the POU tie in points 166, 167, 168, 169, and through the in-linemetrologies 161, with flow monitoring and change detection monitor 100,pressure control and monitor sensors 163, flow directional valve 164 tothe inlet of pump 160, with the tie point to flow sensor 159. Thisprocess can continue until the one or more of the POU opens and beginsusing. Flow sensor 159 in conjunction with flow sensor 162 detects theusage with the rate of use while the blender turns on simultaneously andprovides the blend at the calculated mass balance. When the POU stopstaking, flow sensor 159 in conjunction with flow sensor 162 will detectthe change and the blend will continue until flow sensor 159 full volumeis indicated, at which point the process repeats and continues.Additional in-line heat trace or in line heaters can be added tomaintain loop temperature. If the material in the circulation loopdegrades, directional valve 164 alters state to drain 165 until thesolution is back within the specification limits as detected bymetrologies 161. At this point directional valve 164 again alters stateto resume the circulation through flow sensor 159 and pump 160. Theprocess may repeat as described continuously as long as demand isrequested by the POUs.

While specific embodiments used for illustration purposes in thedisclosure have two or three input branches, any number of inputs may beused. Similarly any number of POUs may be used. FIGS. 5-8 illustrateexemplary alternative embodiments, but do not provide an exhaustive listof all possible embodiments based on the present teachings, as will beappreciated by a person of ordinary skill.

With reference to FIG. 5, an alternative embodiment of a two-componentblending system 500 with no circulating flow is shown. FIG. 5 includes apressurizing gas 171 and exhaust 172. Individual boxes of the blockdiagram are connected and contain components as described above, butrearranged as shown. The same is true with respect to FIGS. 6-8. FIG. 6shows another alternative embodiment of a two-component blending system600, again with no circulating flow. FIG. 7 shows a further alternativeembodiment of a two-component blending system 700 with no circulatingflow and no additional PFC. FIG. 8 shows a further alternativeembodiment of a two-component blending system 800. The embodiment ofFIG. 8 has no circulating flow, no additional PFC, and no temperatureblend.

FIG. 11 is an embodiment of a method of providing a blended mixture to apoint of use, such as a semiconductor processing tool. The method can beperformed in any of the blending system embodiments disclosed herein.The method includes providing a flow of a first species and a secondspecies to a blending unit. The first species and the second species caneach be an aqueous acid, base, solvent, salt, or slurry. The firstspecies and/or second species can each be in a solution. The firstspecies and the second species are blended in the blending unit toproduce a mixture. The mixture is distributed to a point of use via anoutput in fluid communication with the blending unit. The blending unitcan deliver the mixture on-demand to the point of use. The blending unitand/or distribution unit to the point of use has a selected volume.

Some specific examples of the first species and second species includeHF, tetramethylammonium hydroxide (TMAH), surfactants such as ethyleneglycol (EG), H₂SO₄, NH₄OH, NH₄F, or slurries used for CMP.

In a particular example, the blending system mixes DPS+, which is a mixof HF, H₂SO₄, H₂O₂, and H₂O. It can be blended at various temperaturesand concentrations. The HF may be mixed to be 0.01 wt % HF in the DPS+.The blending system can deliver HF within +/−1% relative to the target.In tests with systems using the mass balance described herein, the HFwas delivered with less than 0.001% variance on a target, H₂O₂ wasdelivered with less than a 0.010% variance on target, and H₂SO₄ wasdelivered with less than a 0.012% variance on target.

The flow rate of the first species may be less than approximately 10 lpmand the flow rate of the second species may be less than approximately20 lpm. The blending system can have maximum mixture flowrates of 10,20, 40, 60, or 100 lpm. Sub 0.1 lpm flowrates for the mixture are alsopossible using the blending system. For example, flowrates of less than3.0 mlpm have been achieved. Other flow rates are possible.

A concentration of the first species in the flow of the first species ismeasured with a first metrology system. A concentration of the secondspecies in the flow of the second species is measured with a secondmetrology system.

Using a controller in electronic communication with the first metrologysystem and second metrology system, a concentration in the mixture canbe maintained within 1% of a concentration range of a mixture. Themaintaining includes determining a mass balance to maintain theconcentration in the mixture within 1% of the concentration range usinginformation from the first metrology system, the second metrologysystem, and a flow in the output to the at least one point of use. Themixture can be distributed to multiple points of use. Maintaining theconcentration may be automatically performed by the controller and canoperate in real-time to adjust for changes in concentration or changesin flow to the point of use. The concentration of each species in themixture can be from 0% to less than 100% or greater than 0% to less than100%.

The maintaining can include, using the controller, changing a flow rateof the flow of the first species or a flow rate of the second species.The method can further include increasing or decreasing at least one ofthe flow of the first species or the second species when theconcentration in the mixture is outside the concentration range. Theblending unit can maintain the concentration of the mixture within 1% ofthe concentration range. The concentration range can be measured at thepoint of use or within the blending unit and/or distribution unit to thepoint of use. One or more of the first species, second species, oradditional species can be maintained within the 1% of the concentrationrange in the mixture.

The maintaining also can include, using the controller, increasing aflow of the mixture to the point of use when the concentration in themixture is outside the concentration range. Increasing the flow caninclude opening a drain valve in fluid communication with the blendingunit.

In an instance, the maintaining includes compensating for decompositionof the first species or the second species in the blending unit.

The method can include measuring the concentration in the mixtureupstream of the point of use with an output metrology system.Information from the output metrology system can be used to determinethe mass balance.

Determining the mass balance to maintain the concentration in themixture can include using information about concentration from the pointof use.

The blending system can be configured to provide the mixture to thepoint of use at a plurality of flow rates sequentially over a period oftime. The concentration in the mixture can be within 1% of theconcentration range for the plurality of flow rates. For example, eachof the plurality of flow rates are from 1 liter per minute to 20 litersper minute. Other flow rates are possible.

In an instance, a flow of a third species is provided to the blendingunit. A concentration of the third species in the flow of the thirdspecies is measured with a third metrology system that is in electroniccommunication with the controller. Determining the mass balance can useinformation from the third metrology system. The third species maydecompose at least one of the first species or the second species in themixture.

In an example, the target concentration of mixture at the point of useis approximately 5.5% by weight of the first species and approximately1% by weight of the second species. Other concentrations are possible.

While disclosed with respect to semiconductor processing, embodimentsdisclosed herein can be applied to pharmaceutical processing, biomedicalprocessing, food processing, beverage processing, household productprocessing, personal care product processing, petroleum productprocessing, other chemical processing, and other general industrialliquid product processing.

Various modifications and additions can be made without departing fromthe scope of this disclosure. Features of each of the variousembodiments described above may be combined with features of otherdescribed embodiments as appropriate in order to provide a multiplicityof feature combinations in associated new embodiments. Furthermore,while the foregoing describes a number of separate embodiments, what hasbeen described herein is merely illustrative of the application of theprinciples of the present disclosure. Additionally, although particularmethods herein may be illustrated and/or described as being performed ina specific order, the ordering is highly variable within ordinary skillto achieve aspects of the present disclosure. Accordingly, thisdescription is meant to be taken only by way of example, and not tootherwise limit the scope of this disclosure.

Although the present disclosure has been described with respect to oneor more particular embodiments, it will be understood that otherembodiments of the present disclosure may be made without departing fromthe scope of the present disclosure. Hence, the present disclosure isdeemed limited only by the appended claims and the reasonableinterpretation thereof.

What is claimed is:
 1. A blending system for maintaining a mixture at adesired concentration comprising: a first species input that provides afirst species; a second species input that provides a second species; ablending unit in fluid communication with the first species input, thesecond species input, and an output that is in fluid communication withat least one point of use, wherein the blending unit is configured toblend the first species and the second species thereby forming amixture, wherein the blending unit comprises: an input flow path; anoutput flow path; a chemical injection nozzle proximate the input flowpath, wherein the chemical injection nozzle includes an insertableinjection nozzle; a directional flow perforated plate downstream of theinput flow path and the chemical injection nozzle; a homogenizingturbulence mix zone void disposed downstream of the input flow path andthe chemical injection nozzle and upstream of the directional flowperforated plate; a flow directional cone disposed downstream of theinput flow path and the chemical injection nozzle and upstream of thehomogenizing turbulence mix zone void; a first mixing zone flowdirectional cone disposed downstream of the homogenizing turbulence mixzone void and upstream the directional flow perforated plate; and aturbulence break void disposed between the directional flow perforatedplate and the output flow path; a first metrology system configured tomeasure a concentration of the first species in the first species input;a second metrology system configured to measure a concentration of thesecond species in the second species input; and a controller inelectronic communication with the blending unit, the first metrologysystem, and the second metrology system, wherein the controller isconfigured to: determine a mass balance to maintain a concentration inthe mixture within 1% of a concentration range using information fromthe first metrology system, the second metrology system, and a flow inthe output to the at least one point of use; and maintain theconcentration in the mixture within 1% of the concentration range bycontrolling a flow rate for at least one of the first species or thesecond species to the blending unit based on the mass balance.
 2. Theblending system of claim 1, further comprising: a first species sourcein fluid communication with the first species input, wherein the firstspecies source provides the first species; and a second species sourcein fluid communication with the second species input, wherein the secondspecies source provides the second species.
 3. The blending system ofclaim 1, further comprising an output metrology system in the blendingunit, wherein the output metrology system is configured to measure theconcentration in the mixture upstream of the point of use, wherein theoutput metrology system is in electronic communication with thecontroller, and wherein the controller uses information from the outputmetrology system to determine the mass balance.
 4. The blending systemof claim 1, wherein the system further comprises a plurality of thepoints of use each having one of a plurality of the outputs.
 5. Theblending system of claim 1, wherein the controller is further configuredto: receive information related to a demand rate at the point of use;and increase a flow rate of the mixture from the blending unit to thepoint of use while maintaining the concentration within 1% of theconcentration range.
 6. The blending system of claim 1, wherein thecontroller is further configured to: receive information related to ademand rate at the point of use; and decrease a flow rate of the mixturefrom the blending unit to the point of use while maintaining theconcentration within 1% of the concentration range.
 7. The blendingsystem of claim 1, wherein the blending unit is configured to achieve ahomogenous solution of the mixture at less than 99% of a maximumdesigned flow rate for the system.
 8. The blending system of claim 1,further comprising a directional valve in fluid communication with theblending unit, wherein the controller is in electronic communicationwith the directional valve, and wherein the controller is configured tocontrol the directional valve to circulate or drain the mixture in theblending unit.
 9. The blending system of claim 8, further comprising aheater, a pressure control, and a pump in fluid communication with theblending unit between the blending unit and the output.
 10. The blendingsystem of claim 1, wherein the blending system is configured to providethe mixture to the output at a plurality of flow rates sequentially overa period of time, and wherein the concentration in the mixture is within1% of the concentration range for the plurality of flow rates.
 11. Theblending system of claim 1, wherein the controller is configured tocontrol the blending unit and a flow rate of the mixture to the outputsuch that a first species in the mixture from the first species input ismaintained within a range of approximately 0.01% to approximately 0.1%of the concentration range and such that a second species in the mixturefrom the second species input is maintained within a range ofapproximately 0.01% to approximately 0.1% of the concentration range.12. The blending system of claim 1, further comprising a third speciesinput in fluid communication with the blending unit and a thirdmetrology system in electronic communication with the controller,wherein the third species input provides a third species for themixture, wherein the third metrology system is configured to measure aconcentration of the third species in the third species input, andwherein the concentration of the third species is used in the massbalance.
 13. The blending system of claim 1, further comprising anultra-pure water input in fluid communication with the blending unit.14. The blending system of claim 1, wherein the point of use is asemiconductor processing tool.
 15. A method of providing a blendedmixture to a point of use comprising: providing a flow of a firstspecies to a blending unit; providing a flow of a second species to theblending unit; blending the first species and the second species in theblending unit to produce a mixture, wherein the blending unit comprises:an input flow path; an output flow path; a chemical injection nozzleproximate the input flow path, wherein the chemical injection nozzleincludes an insertable injection nozzle; a directional flow perforatedplate downstream of the input flow path and the chemical injectionnozzle; a homogenizing turbulence mix zone void disposed downstream ofthe input flow path and the chemical injection nozzle and upstream ofthe directional flow perforated plate; a flow directional cone disposeddownstream of the input flow path and the chemical injection nozzle andupstream of the homogenizing turbulence mix zone void; a first mixingzone flow directional cone disposed downstream of the homogenizingturbulence mix zone void and upstream the directional flow perforatedplate; and a turbulence break void disposed between the directional flowperforated plate and the output flow path; distributing the mixture to apoint of use via an output in fluid communication with the blendingunit; measuring a concentration of the first species in the flow of thefirst species with a first metrology system; measuring a concentrationof the second species in the flow of the second species with a secondmetrology system; and maintaining, using a controller in electroniccommunication with the first metrology system and second metrologysystem, a concentration in the mixture within 1% of a concentrationrange based on a mass balance, wherein the maintaining includesdetermining the mass balance to maintain the concentration in themixture within 1% of the concentration range using information from thefirst metrology system, the second metrology system, and a flow in theoutput to the at least one point of use.
 16. The method of claim 15,wherein the blending unit delivers the mixture on-demand to the point ofuse.
 17. The method of claim 15, wherein the maintaining includes, usingthe controller, changing a flow rate of the flow of the first species ora flow rate of the second species.
 18. The method of claim 15, whereinthe maintaining includes, using the controller, increasing a flow of themixture when the concentration in the mixture is outside theconcentration range.
 19. The method of claim 18, wherein increasing theflow includes opening a drain valve in fluid communication with theblending unit.
 20. The method of claim 15, further comprising measuringthe concentration in the mixture upstream of the point of use with anoutput metrology system, wherein information from the output metrologysystem is used to determine the mass balance.
 21. The method of claim15, wherein determining the mass balance to maintain the concentrationin the mixture includes using information about concentration of themixture from the point of use.
 22. The method of claim 15, furthercomprising increasing at least one of the flow of the first species orthe second species when the concentration in the mixture is outside theconcentration range.
 23. The method of claim 15, further comprisingdecreasing at least one of the flow of the first species or the secondspecies when the concentration in the mixture is outside theconcentration range.
 24. The method of claim 15, wherein the system isconfigured to provide the mixture to the point of use at a plurality offlow rates sequentially over a period of time, and wherein theconcentration in the mixture is within 1% of the concentration range forthe plurality of flow rates.
 25. The method of claim 24, wherein each ofthe plurality of flow rates are from 1 liter per minute to 20 liters perminute.
 26. The method of claim 15, wherein distributing the mixture isto a plurality of the points of use.
 27. The method of claim 15, whereinthe maintaining includes compensating for decomposition of the firstspecies or the second species in the blending unit.
 28. The method ofclaim 15, further comprising: providing a flow of a third species to theblending unit; and measuring a concentration of the third species in theflow of the third species with a third metrology system that is inelectronic communication with the controller; wherein determining themass balance uses the concentration of the third species from the thirdmetrology system.
 29. The method of claim 28, wherein the third speciesdecomposes at least one of the first species or the second species inthe mixture.
 30. The method of claim 15, further comprising providing aflow of ultra-pure water to the blending unit.
 31. The method of claim15, wherein the first species and the second species are each an aqueousacid, base, solvent, salt, or slurry.